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America, with its frequent changes of administration SOME RECENT WORKS ON PHYSIOLOGY. and its too often objectionable policy of the spoils to the victors, renders such problems as the economic

On Carbohydrate Metabolism, with an Appendix on

the Assimilation of Carbohydrate into Proteid and and sanitary disposal of city refuse much more difficult to solve than in the case of the cities of Europe,

Fat, followed by the Fundamental Principles and where the municipal engineering and sanitary staff

the Treatment of Diabetes, dialectically discussed.

Dr. have much greater influence and powers of control.

By F. W. Pavy, F.R.S. Pp. xi + 138.

(London : J. and A. Churchill, 1906.) Price 6s. (2) Called upon to remedy defects in existing

net. crematories in the United States, Mr. Venable has

The Dynamics of Living Matter. By Prof. Jacques made a complete study of the principles of design of

Loeb. every type of crematory so far built in the States, and

(Columbia University Biological Series, this book is the result. In an introductory chapter

No. 8.) Pp. xi +233. (New York : The Columbia the author points out that the crudity of the methods

University Press; London: Macmillan and Co., of disposal still in use in many cities is almost in

Ltd., 1906.) Price 12s. 6d. net.

Geschmack und Geruch. credible, and he traces much of the slow progress of

By Dr. Wilhelm Sternreform in this matter to the frequent changes in the

berg. Pp. viii + 149. (Berlin: Julius Springer, administrative officials. In the second chapter tables

1906.) Price marks.

4 are given as to the quantities which have to be DR.

R. PAVY’S new book on carbohydrate metabolism collected, and the average composition of the refuse deals with a subject to which he has devoted in a few large cities; in four cities in the States the a long life of study and original research, and his weight per head per annum ranges from 1140 lb. to opinions are therefore entitled to the most careful 1670 lb.

consideration and respect. He treats the subject The problem of burning refuse without offence is partly from the physician's point of view, for the then taken up, and Mr. Venable insists on the abso- disease known as diabetes cannot be properly underlute importance of so designing the furnace that a stood until the nature of the metabolism which the temperature is reached which renders the discharge carbohydrates undergo in health is a matter of certain of odours from the chimney stack impossible. In knowledge. Those acquainted with Dr. Pavy's chapter iv. the various types of crematories are previous writings will be aware that he has never divided up into classes, based on the fact that there accepted the glycogenic theory of Claude Bernard, is, or is not, some attempt at preliminary drying; and in the present brochure he brings forward fresh each class is then described in some detail, and illus- evidence of what he regards as its incorrectness. Dr. trations are given of a well-known example of each Pavy also was the first to direct attention to the class, and lists of all the patents so far granted in glucoside nature of the proteids, and this view is also the States for such crematories; the next chapter amplified. Most attention, however, will be centred deals with the cost of working destructors, and the on the new doctrine of absorption he puts forward, heat available from the products of combustion for and to the important role in this process which he steam raising.

assigns to the lymphocytes. He supposes that what In chapter vi. a complete history is given of the first occurs is that these cells assimilate nutrient building of crematories in the States from 1887, the matter and incorporate it in their protoplasm, and pioneer year, to the present date, and sectional draw- subsequently carry it to the tissues. Among other ings are reproduced of many of the furnaces which facts in support of this view he directs attention have been put up during that period. Mr. Venable to the great increase in the lymphocytes of the is an advocate for the separate collection of garbage, blood after a meal. One imagines this view will refuse, and ashes, and, therefore, while quite ready not be immediately accepted, partly because it is to admit that the destruction of refuse in England, doubtful whether the lymphocytes are sufficiently where usually the whole of the refuse is collected in numerous, or capable of sufficiently rapid integration one receptacle, is admirably carried out at the pre- and disintegration to bear the burden of the large sent day, he does not think that the British type of amount of material which has to be transported, and destructor is ever likely to come into extensive use partly because the acceptance of such a theory will in America; he, however, gives details of some of the involve the rejection of much recent physiological tests carried out on Meldrum furnaces in Great work in which it has been shown that the foodBritain. In the last three chapters the materials proteids are broken down during digestion into the and methods of construction likely to give the most small molecules of the amino-acids of which they satisfactory results are discussed, and, lastly, a draft are composed. Dr. Pavy has produced an interesting specification is given.

and suggestive book, but he has made no experiThese two books will be extremely interesting to mental attempt to disprove the new ideas of complete English municipal authorities, because they deal fully hydrolysis of proteids in the intestine which are with the methods of disposal of city refuse in the rapidly gaining credence. United States, methods which differ radically from Prof. Jacques Loeb's book is the outcome of a series those in use in our own country, and, while still of lectures he gave at Columbia University in 1902. convinced that we are ahead of our Transatlantic He has entitled it the “ Dynamics of Living Matter," cousins in this important sanitary problem, neverthe- and it is an attempt to explain the phenomena of life less there is much we can learn from them.

on the basis of physical chemistry. Prof. Loeb has

been an arduous worker at this branch of science, This contains somewhat more than 150,000 electrons, and it will be convenient to have in a compact form

and some of the heavier atoms are even more the outcome of his numerous fuller publications,

complex.” which it is the object of this book to present. Prof. The author, by thus presenting so dogmatically Loeb's name is best known in connection with ti.cz and literally the speculations which have centred parthenogenesis which he has artificially produced in

around the electron as the basis of matter, has unfertilised marine eggs, by altering the saline con- directed attention away from the solid experimental stituents and other physical conditions of the surround- work on which our knowledge of the nature of ing water. This subject is here given in its most electrons rests. It is this work, and not the sweeping recent developments, but the book naturally contains electronic hypothesis, which is connected with radioa good deal in addition. We may regard the work activity. But for the pioneer work on the ionisation as a useful counterblast to those who term themselves of gases done in the Cavendish Laboratory and elseneo-vitalists. It can hardly be considered the last where, the electrical method of radio-active measureword on the subject. Physical chemistry in relation to

ment could not have reached its present perfection, inorganic material is in a state of flux, one theory and it is safe to say that, deprived of this method, displacing others with startling rapidity. It is, there- radio-activity would have advanced but slowly. But fore, a little early to apply it to organic and living whether the atom of mercury has 200 or 150.000 substances with any hope of obtaining universal electrons is a question which fortunately has nothing acceptance of the theories put forward. The specula- to do with the very fundamental and independent tions indulged in are interesting, and the facts will conclusions of the nature of matter formed from settle down into their proper places later on.

radio-active evidence. The third book in this physiological batch relates Radio-activity, the second topic, is started in to a small corner of physiological inquiry, namely, chapter v., and with the remainder of the work and taste and smell, and mainly the former. Dr. Stern- the mode of treatment no exception can be taken. berg has devoted attention to this sub-branch of a except that it is not very up-to-date. The last branch of physiology, and has produced a readable chapter, which is entitled “ Most Recent Work in pamphlet. It is, however, a little difficult to under- Radio-activity," attempts, however, to accomplish stand why books should be written with such limited this. scope, and it is doubtful if they are really needed. The book as a whole gives a comprehensive and

interesting survey of the radio-activity of matter as

it is interpreted by the disintegration hypothesis MATTER AND RADIO-ACTIVITY.

Perhaps the best chapters are those dealing with the

reproduction of radio-active matter and the theor The Electrical Nature of Matter and Radio-activity. arising therefrom. Here the chemical training and

By Prof. Harry C. Jones. Pp. ix +212. (London : point of view of the author are in evidence, and the Archibald Constable and Co., Ltd., 1906.) Price

significance of the continuous reappearance of the 75. 6d, net.

products of change after complete removal by THIS CHIS book consists of a series of articles, written chemical or other means is very clearly brought out.

in semi-popular style, reprinted from the Attention may be directed to some inaccuracies and Electrical Review. The first third of the book is errors of minor importance. The author does not occupied with the electronic theory of matter, and seem very clear about the nature and properties of follows the usual popular lines. The subject is treated the y rays. We learn that their power to affect the only from what may be called the Cavendish Labor- photographic plate is much greater than that of the atory point of view, and, in fact, we read that we owe B or even the a particles, an error which is frequently the whole electronic conception to Prof. J. J. repeated. Their origin is ascribed to the impact of Thomson. The optical and spectroscopic foundations B rays on solid matter rather than to the acceleration for the theory are omitted, and the names of Larmor, of the B particle during expulsion. In the experiH. A. Lorentz, and Zeeman are not mentioned. ment of causing, by means of a glass tube containing

It is difficult to attempt to review this part of the radium, a discharge to pass between two points just book, for if the reviewer has interpreted a

so far apart that ordinarily the spark fails, most of paper by Prof. J. J. Thomson aright, the view that the ionisation from the glass tube is ascribed to the the constituent electrons of an atom are present in v rays. It is safe to say that if the glass were 5 sufficient numbers to contribute any appreciable part thick as this the experiment would fail. The stateof its mass appears to have been disproved. Here, ment that the emanation can be condensed at low however, we read :

temperatures like an ordinary gas into a liquid i “ There is one point at least brought out so clearly obviously a slip, for a little later we read that no liquid that there can scarcely be any question about it, and or even mist will be seen. Twice later, however, the that is that matter is a pure hypothesis.”

statement is repeated, and liquid appears a look

word for non-gaseous. The B rays are ascribed little And again :

power of exciting phosphorescence, and the effect a “ The atom according to this theory is very a platino-cyanide screen is said to be greater for, complex. Take, for example, the atom of mercury. than for B and q rays.

recent

OUR BOOK SHELF.

It would not be correct to say that Mr. Black is

always exact in his descriptions; he is apt to be someRésistance, Inductance et Capacité. By M. J. Rodet.

what loose, and his book suggests that he has not Pp. X+257. (Paris : Gauthier-Villars, 1905.)

consulted the most recent authorities. But he is This book is devoted entirely to the three subjects never so far wrong as to be misleading. He may which form the title, and it has evidently been the puzzle the student by apparent contradictions, due to author's aim to include everything within the limits the introduction or exclusion of circumstances which mentioned likely to

be of use to engineers or can exercise an important influence upon the point physicists.

under consideration. Particularly would we caution is a whole the author has succeeded, and has pro- the student to beware of those explanations for which duced a valuable book of reference. The subjects are the author himself is responsible, and in which he treated in the order mentioned. Under the heading seeks to remove difficulties that have not yet received of resistance, in addition to the usual constants, in- a satisfactory solution. An example will be found in formation is given as to the conductivities of insu- the discussion on the semi-diurnal barometric inlators, solid and liquid, and the insulation due to a equality. The author seems, too, to have lost his way film of oil between a rotating shaft and its bearings. in the chapter on weather cycles; but the book is In account is given of the various rectifiers, including calculated to arouse interest. to stimulate curiosity, the Cooper-Hewitt.

to promote further study, and on these grounds one L'nder the heading of inductance a full and clear may welcome its appearance. The illustrations are statement is given of the usual phenomena, and the generally effective, and a very good index accompanies various methods of calculating coefficients of self- the book. and mutual inductance are explained, but no mention is made of a rectangular coil such as is used in

A Text-book of General Zoology. By Dr. Henry R. certain instruments of the dynamometer style. The

Linville and Dr. Henry A. Kelly. Pp. x+ 462 ; inductance of cables is also studied, and a reference

illustrated. (London and Boston : Ginn and Comis made to the apparent increase of resistance of

pany, 1906.) Price 7s. 6d. conductors traversed by alternating currents, but no mention is made of the internal self-induction of an This addition to the long shelf of text-books of iron rail, which is an important factor in the appli- zoology has some fresh features. Practical experication of alternating currents to electric traction. ence has led the authors to begin with the Arthropods,

The initial portions of that part of the book which work down to the Protozoa, and then ascend the is devoted to the study of capacity follow the ordinary vertebrate series. The study of insects has been found methods of exposition. Tables of specific inductive the best introduction to the broad problems of zoology, capacity of various substances are given, and inform- and in the earlier chapters a modified inductive ation is presented as to the variation of this property method is pursued. About half-way through the with temperature. Following this, the distribution of book, after the student has become familiar with the potential in a compound condenser is described, systems of organs, he is introduced to physiological as, for instance, in a condenser in which the dielectric principles, illustrated with special reference to the is composed of two plates of glass separated by a earthworm. Throughout the book prominence is layer of air. (This matter is of practical importance given to the study of animal behaviour and the in the building of high-voltage machines, as brought environmental conditions. Thus there is a feeling of out by Messrs. Hobart and Turner in their recent book fresh air through the chapters. The authors have on insulating materials.) A brief reference is made to reacted from the position of identifying zoology with the electrodynamic condenser proposed by Mr. Swin- comparative anatomy, and the introduction to the burne, and a section is devoted to the study of science which they have presented seems to us, not capacity effects due to cables and overhead trans- only interesting, but educationally wholesome. Most mission lines.

of the illustrations are original, and many of them The book would have been more complete if the are beautiful. researches of the late Dr. John Hopkinson had been referred to as to the specific inductive capacity of Science Readers. Book VII. By Vincent T. Murché. materials at

very
low temperature.

For practical Pp. 299. (London : Macmillan and Co., Ltd., 1906.) men, however, this volume contains almost everything Price is, ed. that they are likely to want, and to them it can be

Object Lessons in Elementary Science. Stage VII. thoroughly recommended.

By Vincent T. Murché. New and revised edition. Vatural Phenomena. A Collection of Descriptive and

Pp. xvi + 322. (London : Macmillan and Co., Ltd., Speculative Essays on some of the By-paths of

1906.) Price 2s. Nature. By F. A. Black. Pp. xiv + 366. (London THESE books deal with elementary physics. The first and Edinburgh : Gall and Inglis, n.d.)

is intended for pupils to read in class, lesson by In this book Mr. Black offers some essays which lesson, after they have attended an explanatory and might well be of value to the student of physio- | experimental demonstration from the teacher on the graphy, Treatises this subject usually subject in hand. The second book contains notes of crammed very full of facts, and more interest might lessons designed only for the use of teachers. The be awakened and a wider horizon opened to the notes are accompanied by helpful advice, blackboard student, if he reads such a work as this in connection sketches, and many other evidences of the wide experiwith the ordinary text-books. There are ten essays ence of the author. Both volumes are attractively altogether; four deal with some points connected illustrated and well printed, though it may well be with our own atmosphere, and four discuss problems doubted if the bewildering profusion of types in the of elementary astronomy, arising mainly from the second book adds to its helpfulness. The author is a motion of the earth on its axis. The remaining two master of simplicity of expression, and the informtreat of the Sargasso Sea and the Zodiacal Light with ation he supplies is, as a rule, trustworthy. The its allied phenomena. These seem to be highways books deserve the careful consideration of teachers of rather than by-paths.

very elementary classes.

on

are

occurs

at

an

LETTERS TO THE EDITOR.

of charcoal can be utilised to determine quantitatively the

amount of radium emanation existing in the air, and also [The Editor does not hold himself responsible for opinions the amount of emanation diffusing to the atmosphere from expressed by his correspondents. Neither can he undertake the soil.

E. RUTHERFORD. to return, or to correspond with the writers of, rejected McGill University, Montreal, October 6. manuscripts intended for this or any other part of NATURE. No notice is taken of anonymous communications.)

The Recent Radium Controversy. Absorption of the Radio-active Emanations by

I was absent from Montreal during the time of the Charcoal.

interesting discussion on radium which appeared in the The interesting property of certain kinds of charcoal, Times, and it is only quite recently that I have had an notably that of the cocoa-nut, of rapidly absorbing gases,

opportunity of reading the correspondence in full. In the except the inert gases belonging to the argon family, is course of this discussion some weight has been attached now well known since the recent experiments of Sir James to a remark in the second edition of my book “ RadioDewar.

activity,” viz. that radium is a compound of helium and In a recent investigation I had occasion to pass the

lead. It is far from my intention to reopen this discussion, radium emanation through a tube filled with cocoa-nut

on which I think quite enough has already. been said, but charcoal, and was surprised to find that the emanation was in the last issue of NATURE (September 27) which I have completely absorbed by it. If a slow current of air, mixed just received, there appears a letter by Lord Kelvin in with the emanation of radium, thorium, or actinium, is which this remark is still further emphasised. passed through a tube filled with charcoal, the issuing gas Lord Kelvin quite correctly quotes my words, but I fei is completely deprived of emanation. This

that the statement, apart from its context, is liable to leave ordinary temperatures, and there is no necessity for initial erroneous impression of my views on the question cooling of the charcoal. This property of charcoal of especially in the minds of those who are not directly absorbing the radium emanation can be shown by a very

acquainted with my writings. simple and striking experiment. If a side tube containing

At the risk of being somewhat lengthy, I should like to a fraction of a gram of charcoal is attached to a vessel quote fully some statements made in my book which, I containing the emanation released from several milligrams think, clearly show my attitude on this question. of radium bromide, in the course of time the emanation is V. p. 482 :--" In order to explain the presence of absorbed by the charcoal. At ordinary temperatures, several

helium in radium on ordinary chemical lines, it has been hours or days, depending on the size of the vessel, are suggested that radium is not a true element, but a molecular required to effect a complete absorption as the emanation compound of helium with some substance known or undiffuses slowly through the air.

If some
powdered known.

The helium composed gradually breaks down willemite is added with the charcoal, the gradual absorp- giving rise to the helium observed. It is at once obvious tion of the emanation is shown by the increasing brilliancy that this postulated helium compound is of a character of the phosphorescence produced in the surrounding entirely different from that of any other compound pres willemite.

viously observed in chemistry. Weight for weight, it emits It makes no difference whether the charcoal has been during its change an amount of energy at least one million initially heated to get rid of the absorbed air or whether times greater than any molecular compound known (see it has already absorbed its full quantity. At low pressures

section 249). In addition it must be supposed that the of the gas, using charcoal which has been previously rate of breaking up of the helium compound is independent heated, the removal of the emanation takes place rapidly. of great ranges of temperature-a result never before This is probably due to the rapid absorption of the gas observed in any molecular change. The helium compound which carries the emanation with it. The charcoal retains in its breaking up must give rise to the peculiar radiations the emanation at ordinary temperatures, for I have found and also pass through the successive radio-active changes that the emanation retained in a charcoal tube open to observed in radium. the air loses its activity at the normal rate observed in “ Thus in order to explain the production of helium and sealed vessels.

radio-activity on this view, a unique kind of molecule mus The greater part of the emanation is released by heating be postulated-a molecule in fact which is endowed with the charcoal below a red heat. I have not yet settled every single property which on the disintegration theort is whether the release of the emanation is due to an alter- ascribed to the atom of the radio-elements. On the other ation in the absorptive power of the charcoal for the hand, radium, as far as it has been examined, has fulfilled emanation at high temperatures, or whether the emanation every test required for an element. It has a well marked is mechanically carried away by the rush of air which and characteristic spectrum, and there is no reason to suptakes place when the charcoal is heated.

pose that it is not an element in the ordinarily accepted Since the emanations behave like inert gases of the sense of the term. argon family, it is somewhat surprising that charcoal “On the theory that the radio-elements are undergoing should so readily absorb them. It must be remembered, atomic disintegration, the helium must be considered to be however, that in ordinary experiments a very minute a constituent of the radium atom, or in other words, thr quantity of the emanation is present, and it is not unlikely radium atom is built up of parts, one of which, at least that even the gases argon and helium are absorbed by is the atom of helium. ..." charcoal to a small degree.

P. 483 :-" Taking the view that the a particles are pre This property of charcoal of retaining the emanation jected helium atoms, we must regard the atoms of the promises to be of service in laboratories where radium is radio-elements as compounds of some known or unkness to kept in a state of solution. It is dangerous to keep radium substance with helium. These compounds break up spor in the form of solution in sealed vessels, as the gradual taneously, and at a very slow rate even in the case ct production of hydrogen and oxygen in the solution raises radium. The disintegration takes place in successis the internal pressure, which would ultimately lead to the stages, and at most of the stages a helium atom is bursting of the vessel. At the same time, the escape of projected with great velocity. This disintegration is the emanation causes a radio-active contamination of the accompanied by an enormous emission of energy. The laboratory which renders delicate experiments on radio- liberation of such a large amount of energy in the radactivity or ionisation very difficult.

active changes at once explains the constancy of the rate This problem will be solved by the use of a small tube of change under the action of any of the physical and containing cocoa-nut charcoal attached to the vessel, with chemical agencies at command. On this one end open to the air. The air inside the radium vessel uranium, thorium, and radium are in reality compoun** is kept at atmospheric pressure, while the emanation is of helium. The helium, however, is held in such strong completely stopped in the charcoal. The emanation mixed combination that the compound cannot be broken up be with a small quantity of gas can at any time be obtained chemical or physical forces, and, in consequence, threr from the charcoal by heating.

bodies behave as chemical elements in the ordinar lv Experiments are in progress to test whether this property I accepted chemical sense.

our

"It appears not unlikely that many of the so-called spontaneous deserves full investigation, and I think more chemical elements may prove to be compounds of helium, especially with regard to the primary step, the generation or, in other words, that the helium atom is one of the of radium from uranium. If this is dependent on the secondary units with which the heavier atoms are built matrix and on concentration, entirely new considerations up. In this connection it is of interest to note that many arise. of the elements differ in their atomic weight by four-the It is not impossible, in the present meagre state of our atomic weight of helium.

knowledge, that the penetrating radiations observed at the “If the a particle is a helium atom, at least three surface of the earth have to do with the genesis of radium u particles must be expelled from uranium (2385) to re- from uranium, the failure of such rays to penetrate deep duce its atomic weight to that of radium (225). It is into the crust limiting the production. The suggestion is known that five a particles are expelled from radium during continuous with that advanced above.

J. JOLY. its successive transformations. This would make the Geological Laboratory, Trinity College, Dublin. atomic weight of the final residue 225–20 = 205. This is very nearly the atomic weight of lead, 206-5. I have for some time considered it probable that lead is the end or

IN reply to Mr. O. Fisher's interesting letter of final product of radium. The same suggestion has recently

October 11 in this Journal under the above heading, it been made by Boltwood."

may be suggested that, though a state of stable thermal Then follows a discussion of the evidence on which this

equilibrium exists now in the earth, it did not in the suggestion is based.

past, and that the earth has cooled down from a great I think that the above quotation makes my position clear

initial temperature. We are, however, met with this on this subject.

E. RUTHERFORD.

difficulty, that the movements of the crust have been VcGill University, Montreal, October 11.

enormous in late geological tiines, as shown in the great mountain ranges of Tertiary date. This seems to be a fact

entirely antagonistic to the suggested explanation. Radium and Geology.

No doubt some of the current geologico-dynamic theories

will go to the wall should Mr. Strutt's interesting reThe Hon. R. J. Strutt has advanced weighty reasons ! searches be confirmed, but I am of opinion that his work in favour of supposing radium to be confined to a certain will ultimately prove helpful to sounder ideas of the origin shallow layer over the surface of the earth. To assume, of earth structure.

T. MELLARD READE. however, that a heavy element is thus restricted in dis- Park Corner, Blundellsands, October 13. tribution appears to me to present difficulties. It would appear that an a priori probable reason why uranium should disintegrate more rapidly near the surface than at

The age of the great mountain ranges mentioned above by greater depths would bridge over the difficulty, and, if for

Mr. Reade, though comparatively late, is much earlier than that reason only, would deserve attention.

that of the changes of vertical level investigated by Prof. I think such a reconciliation of observational facts with

Hull and Dr. Spencer to which I referred. They are the probabilities involved would be found in the view that

evidenced by the drowned plains bordering the Atlantic on the break up of uranium is not entirely spontaneous, but is

both sides, and by the deep cañons in them which are the partly secondary in character, i.e. that disruption of an

continuations of existing river channels. These changes a particle from an unstable atom_may precipitate the

of level are considered to be of Pliocene or early Pleistocene failure of neighbouring atoms, as Prof. J. J. Thomson date, and, therefore, geologically very recent. Godwin has suggested might happen in the case of radium. If

Austen came to a similar conclusion about the English this be the case, and we assume that the uranium is in

Channel. general distributed in random aggregates throughout the

I thank Mr. Strutt for noticing (p. 610) my letter in earth, a reason is at once forthcoming for Mr. Strutt's

NATURE of October 11. The fact of uranium not having results. The lighter constituents in the outer crust

been recorded in analyses of the rocks, as referred to by aluminium, silicon, oxygen-exert a lesser screening action

Mr. Strutt, has occurred to myself, but not being a chemist than the heavy metals deeper down. The conflagration is, I have not alluded to it. But it seems to me that there as it were, isolated where the heavier metals interpose to

ought to be an appreciable store of uranium present, large absorb the energy of the a ray which initiates the changes

in proportion to the radium it is producing, if the latter is leading to radium. It is probable that if the absorption is not permanent. That there is not appears to indicate that adequate to reduce the kinetic energy below a certain the disintegration of the radium, and therefore the escape critical amount, there would be no propagation of disrup- of heat from it, is in some way checked in the earth's tion.

crust, as suggested by Mr. Rudge in his letter to the Times · The remarkable fact observed in Mr. Strutt's experi- of August 18, and that consequently the temperature ments that radium is more abundant in the heavier silicates gradient is not due to radium in the crust, but to the coolof plutonic rocks than in the lighter is not opposed to

ing of the interior. I think it in this direction that we this view, but rather in keeping with it; and the absence

must seek for a reconciliation between radium and geology, of detectable radium in metallic meteorites need not be Graveley, Huntingdon, October 19.

O. FISHER. occasioned by the absence of uranium, but by the slower breakdown of the latter. I cannot claim to speak authoritatively on the literature

Meteorological Data. of this subject, but I can recall no other experiments bear- I shall be glad if you will enable me through your ing on this matter than those quoted by Prof. Rutherford columns to make known to those interested in the collecin the last edition of his “Radio-activity." The case of tion of meteorological data the following information. uranium does not appear to have been investigated. Prof. A number of copies of the Cape of Good Hope MagRutherford records an experiment in which he dissolved netical and Meteorological Observations, vol. ii., Meteorsome pure radium bromide in 1000 times its bulk of a ological Observations, 1841-6," have been placed at my solution of barium chloride, and found no change in the disposal by the Controller of H.M. Stationery Office for y radiation. I venture to suggest that this experiment is distribution. The volume contains hourly observations, for not conclusive. Increasing the volume 1000 times increases each day, of pressure, temperature, and humidity, with a the average distance of the molecules but ten times, even journal of other meteorological data. were these fixed in the medium. This leaves the inter- I shall be glad if any scientific institution or library vening distances still of the order of millionths of a centi- which desires a copy will be good enough to communicate metre. The heaviest metal brought to such tenuity would with me upon the subject at the Meteorological Office, exert no appreciable screening influence, even from the 63 Victoria Street. a rays, to say nothing of more penetrating radiations. Mr. I have also available for distribution in a similar manner Eve's experiments, which are also quoted by Prof. Ruther- a few copies of the following works :ford, are not, I think, to the point.

Meteorological Observations taken during the Years As cosmical effects of the greatest interest are involved, 1829 to 1852, at the Ordnance Survey Office, Phænix Park, I think the question of how far radio-active effects are Dublin, ... and Other Places in Ireland.”

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